The Obamacare website, which launched October 1, deleted some users' passwords, according to multiple call center representatives for the site.

Five call center agents told CNN on Wednesday that because of an upgrade to the beleaguered website, many passwords were deleted if they were created in the first week or so after the launch. More recently created user names and passwords don't seem to have the same problems.

If the representatives have it right, some users will continue having trouble logging in, no matter how many times they try.

"They did maintenance on the website recently and deleted all the passwords, so they needed resetting," one agent wrote in a live online chat with a CNN reporter who has been attempting to go through the process of using the site.

"They deleted passwords on accident," said another agent who answered the phone at the healthcare.gov call center. "They lost them."

A senior administration official said these call agents are wrong. She said no passwords have been deleted, and the call agents were reading from a script that was given to them by mistake.

She adds that the administration has been trying to get them to stop using that script for the past week.

However, a call center agent said he'd received an e-mail as recently as Monday about the deleted passwords.

The Obamacare call center is run by government contractor Vangent. A spokesman for its parent company, General Dynamics, referred inquiries to the Center for Medicare & Medicaid Services, which is managing the website. A spokeswoman for that agency said she was looking into the issue.

The senior administration official said while no passwords were deleted, some users, especially those who signed up "early on," have been having trouble logging in, and the administration is working on a fix for those users.

"We want to give them really clear instructions that won't be frustrating," the official said.

In the meantime, the official said users who can't log in can get help from the call center at 1-800-318-2596. And if a user chooses to do so, they can start all over again.

"Nothing precludes you from starting a new account. You can certainly do that."